Constrainable stent graft, delivery system and methods of use

ABSTRACT

A stent graft for treating an arterial aneurysm includes a ligature traversing at least a portion of struts of stents, the ligature having ends that, when linked, at least partially constrict a radial dimension of the stents. The ends of the ligature can be linked by a wire in a stent graft delivery system that threads anchor loops longitudinally spanning ends of the ligature to maintain the stent in a radially constricted position during delivery to the aneurysm. The stent graft can be implanted at the aneurysm by retracting the wire from the linked ends of the ligature and from the anchor loops, thereby releasing the associated stent from the radially constricted position.

RELATED APPLICATION

This application is a divisional of U.S. application Ser. No.16/414,292, filed on May 16, 2019, which is a continuation ofInternational Application No. PCT/US2018/019342, which designated theUnited States and was filed on Feb. 23, 2018, published in English,which claims the benefit of U.S. Provisional Application No. 62/463,057,filed Feb. 24, 2017. The entire teachings of the above applications areincorporated herein by reference.

BACKGROUND

Arterial pathologies, including aortic aneurysms, can be treated by opensurgical reconstruction, or alternatively, endovascular repair, which isa minimally invasive alternative to open surgical repair. Optimizing asuccessful outcome of endovascular repair, however, requires assessmentof the patient's anatomy and, in the case of an arterial, or, morespecifically, an aortic aneurysm, an appropriate stent spanning theproximal and distal ends of the aneurysm ensures essentially completeexclusion of the aneurysm sac by anchoring of the stent graft in theaorta to minimize endoleaks. Endoleaks and post-surgical enlargement ofthe aneurysm site often require additional repair to seal any expansionof the aneurysm sac and, generally, must be done without significantlycompromising blood flow through the surgical site to surrounding visceraand associated structures.

Therefore, a need exists for new and improved endovascular repairdevices and methods to treat arterial pathologies, such as aorticaneurysms.

SUMMARY

The present invention relates to stent grafts for use in treating andrepairing aortic and other arterial vascular damage, such as vasculardamage associated with aortic aneurysms, including aortic aneurysms inregions of the aorta having arterial branches that supply blood to vitalorgans and tissues, such as thoracic aortic aneurysms, abdominal aorticaneurysms, thoracoabdominal aortic aneurysms, juxtarenal aorticaneurysms and short-neck abdominal aortic aneurysms.

In one embodiment, the invention is a stent graft that includes aluminal graft component having a proximal open end and a distal openend. A plurality of stents are distributed longitudinally along theluminal graft component, and at least one of the stents has struts thatare joined to define proximal and distal apices. At least one ligaturetraverses at least a portion of the struts of at least one of thestents. The ligature includes ends that, when linked, at least partiallyradially constrict each corresponding stent. A pair of anchor loops atthe luminal graft component longitudinally span the ends of eachassociated ligature when linked to radially constrict the correspondingstent.

In another embodiment, the invention is a stent graft delivery systemthat includes a stent graft. The stent graft includes a luminal graftcomponent having a proximal open end and a distal open end, and definesa lumen. A plurality of stents are distributed longitudinally along theluminal graft component, and at least one of the stents has struts thatare joined to define proximal and distal apices. At least one ligaturetraverses at least a portion of the struts. The ligature includes endsthat, when linked, at least partially radially constrict the stent. Apair of anchor loops at the luminal graft component longitudinally spanthe ends of each associated ligature when linked to radially constrictthe corresponding stent. A wire extends longitudinally along the luminalgraft component, and through the anchor loops, linking the ligature endsand thereby radially constricting at least a portion of the stents ofthe stent graft, whereby retraction of the wire from the ends of the atleast one ligature releases the ends of stent graft from constriction bythe at least one ligature.

In still another embodiment, the invention is a method of implanting astent graft at an arterial aneurysm of a subject. The method includesadvancing a stent graft to an arterial aneurysm of the subject, whereinthe stent graft includes at least one ligature extending about aperiphery of the stent graft, the ligature traversing struts of a radialstent of the stent graft and having ends that are linked by a wireextending parallel to a longitudinal axis of the stent graft and throughanchor loops longitudinally spanning the linked ends to thereby maintainthe stent graft in a radially constricted position. The wire isretracted from the at least one ligature and the anchor loops,consequently releasing the ends of the ligature from each other, wherebythe stent graft radially expands from the radially constricted positionto a radially expanded position, thereby implanting the stent graft atthe arterial aneurysm of the subject.

This invention has many advantages. For example, the physician canrotate or reposition the stent graft after it has been partiallydeployed to align a fenestration in the stent graft with a branchvessel, such as by only partially retracting the wire radiallyconstricting stents of the stent graft, thereby providing greatercontrol over delivery systems that are only able to position the stentgraft before deployment begins. As a consequence, a stent graft can bedeployed at a surgical site with more accuracy, less risk of injury tothe vasculature of the subject, and without significant risk ofdistorting the intended shape of the stent graft when implanted at thesurgical site.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing will be apparent from the following more particulardescription of example embodiments, as illustrated in the accompanyingdrawings in which like reference characters refer to the same partsthroughout the different views. The drawings are not necessarily toscale, emphasis instead being placed upon illustrating embodiments. Thesame number present in different figures represents the same item.

FIG. 1A is a side view of one embodiment of a stent graft deliverysystem of the invention, wherein a stent graft is in a radiallyconstricted position, and a wire maintaining the stent graft in aradially constricted position is stabilized by anchor loops.

FIG. 1B is an end view of the stent graft delivery system of FIG. 1A,taken along line 1B-1B, and having diameter D′.

FIG. 1C is a side view of the proximal end of the stent graft of FIG. 1Btaken along line 1C-1C.

FIG. 1D is a side view of the proximal end of the stent graft of FIG. 1Btaken along line 1D-1D.

FIG. 1E is a side view of the proximal end of the stent graft of FIG. 1Btaken along line 1E-1E.

FIG. 1F is a side view of the proximal end of the stent graft of FIG. 1Btaken along line 1F-1F.

FIG. 2A is a side view of the stent graft shown in FIGS. 1A-1F,following retraction of the wire linking ligatures holding the stentgraft in a radially constricted position.

FIG. 2B is an end view of the proximal end of the stent graft in anunconstricted position, as shown in FIG. 2A, taken along line 2B-2B, andhaving an expanded diameter D″.

FIG. 2C is a side view of the proximal end of the stent graft shown inFIG. 2B, taken along line 2C-2C.

FIG. 2D is a side view of the proximal end of the stent graft shown incross-section in 2B, taken along line 2D-2D.

FIG. 2E is a side view of the proximal end of the stent graft shown inFIG. 2A and shown in cross-section in FIG. 2B, taken along line 2E-2E.

FIG. 2F is a side view of the proximal end of the stent graft shown inFIG. 2B taken along line 2F-2F.

FIG. 3A is another embodiment of a stent graft delivery system of theinvention, wherein a stent graft of the stent graft delivery system isheld in a radially constricted position by a wire stabilized by anchorloops, and wherein the ligatures are stabilized by ligature loopsdistributed laterally on either side of the wire.

FIG. 3B is an end view of the stent graft delivery system shown in FIG.3A, taken along line 3B-3B, showing the stent graft as having aconstricted diameter D′.

FIG. 3C is a side view of the proximal end of stent graft shown in FIG.3B, taken along line 3C-3C.

FIG. 3D is a side view of the proximal end of the stent graft shown inFIG. 3B, taken along line 3D-3D.

FIG. 3E is a side view of the proximal end of the stent graft shown inFIG. 3B, taken along line 3E-3E.

FIG. 3F is a side view of the proximal end of the stent graft shown inFIG. 3B, taken along line 3F-3F.

FIG. 4A is a side view of the stent graft of the stent graft deliverysystem shown in FIGS. 3A-3F, following retraction of the wire componentof the stent graft delivery system from end loops of the ligatures andfrom the anchor loops, thereby causing stent graft to expand in diameterto an expanded position.

FIG. 4B is an end view of the stent graft as shown in FIG. 4A, takenalong lines 4B-4B, having an expanded diameter D″.

FIG. 4C is a side view of the proximal end of the stent graft shown inFIG. 4B, taken along line 4C-4C.

FIG. 4D is a side view of the proximal end of the stent graft shown inFIG. 4B, taken along line 4D-4D.

FIG. 4E is a side view of the proximal end of the stent graft shown inFIG. 4B, taken along line 4E-4E

FIG. 4F is a side view of the proximal end of the stent graft shown inFIG. 4B, taken along line 4F-4F.

FIG. 5A is a side view of another embodiment of the stent graft deliverysystem of the invention, wherein ligatures do not completely encompassthe stent graft when the prosthesis is in a radially constrictedposition.

FIG. 5B is an end view of the stent graft delivery system shown in FIG.5A, taken along line 5B-5B, showing the stent graft having a constricteddiameter D′.

FIG. 5C is a side view of the proximal end of the stent graft shown inFIG. 5B, taken along line 5C-5C.

FIG. 5D is a side view of the proximal end of the stent graft shown inFIG. 5B, taken along line 5D-5D.

FIG. 5E is a side view of the proximal end of the stent graft shown inFIG. 5B, taken along line 5E-5E.

FIG. 5F is a side view of the proximal end of the stent graft shown inFIG. 9B, taken along line 5F-5F.

FIG. 6A is a side view of the stent graft of the stent graft deliverysystem shown in FIGS. 5A-5F, following retraction of the wire linkingends of the ligature to hold the stent graft in a radially constrictedposition, wherein retraction of the wire from the anchor loops causesthe stent graft to radially expand to an expanded diameter.

FIG. 6B is an end view of the proximal end of the stent graft shown inFIG. 6A, taken along line 6B-6B, showing the diameter of the radiallyexpanded stent graft as D″.

FIG. 6C is a side view of the proximal end of the stent graft shown inFIG. 6B, taken along line 6C-6C.

FIG. 6D is a side view of the proximal end of the stent graft shown inFIG. 6B, taken along line 6D-6D.

FIG. 6E is a side view of the proximal end of the stent graft shown inFIG. 6 taken along line 6E-6E.

FIG. 6F is a side view of the proximal end of the stent graft shown inFIG. 6B, taken along line 6F-6F.

FIG. 7A is a side view of yet another embodiment of a stent graftdelivery system of the invention, wherein ligatures radiallyconstricting the stent graft are circular and extend about the peripheryof the stent graft, and wherein diametrically opposed points of theligatures are linked by a wire that is stabilized by anchor loops.

FIG. 7B is an end view of the stent graft delivery system of FIG. 7A,taken along line 7B-7B, and having diameter D′.

FIG. 7C is a side view of the proximal end of the stent graft shown inFIG. 7B taken along line 7C-7C.

FIG. 7D is a side view of the proximal end of the stent graft shown inFIG. 7B taken along line 7D-7D.

FIG. 7E is a side view of the proximal end of the stent graft shown inFIG. 7B taken along line 7E-7E.

FIG. 7F is a side view of the proximal end of the stent graft shown inFIG. 7B taken along line 7F-7F.

FIG. 8A is a side view of another embodiment of a stent graft deliverysystem of the invention, wherein the stent graft includes afenestration.

FIG. 8B is a side view of yet another embodiment of a stent graftdelivery system of the invention, wherein the proximal open end includesa scalloped edge.

FIG. 8C is a side view of a further embodiment of a stent graft deliverysystem of the invention, wherein the distal open end includes ascalloped edge.

FIG. 8D is a side view of a further embodiment of a stent graft deliverysystem of the invention, wherein both the proximal and distal open endsinclude a scalloped edge.

FIG. 9 is an exploded side view of one embodiment of a stent graftdelivery system of the invention.

FIG. 10A is a side view of the stent graft delivery system shown in FIG.9 , but in assembled form and, wherein the introducer sheath, containinga stent graft of the stent graft delivery system of the invention, hasbeen delivered to an arterial aneurysm of a patient.

FIG. 10B is a side view of the stent graft delivery system of FIG. 10A,following proximal retraction of the introducer sheath along the stentgraft delivery device, to thereby expose the stent graft, which is heldin a radially constricted position by a wire of the stent graft deliverysystem.

FIG. 10C is a side view of the stent graft delivery system shown inFIGS. 10A and 10B, following partial retraction of the wire fromligatures that, when linked by the wire, holds the stent graft in apartially radially constricted position, while the remainder of thestent graft is in a radially expanded position.

FIG. 10D is a side view of the graft prosthesis delivery system shown inFIGS. 10A-10C, following full retraction of the wire from the stentgraft, whereby the stent graft is in a radially expanded position alongits entire length.

FIG. 10E is a side view of the stent graft delivery system shown inFIGS. 10A through 10D, following retraction of the remainder of thestent graft delivery system not implanted at the aneurysm, wherebyimplantation of the stent graft at the aneurysm of the patient iscomplete.

DETAILED DESCRIPTION

A description of example embodiments follows.

The invention is generally directed to a stent graft and a deliverysystem that includes a stent graft and a plurality of wires extendingthrough the lumen of the stent graft and on each lateral side of afenestration in the stent graft. The invention also is directed to amethod of use of the stent graft and delivery system of the invention.The stent graft delivery system and method of its us treat aorticvascular damage, such as vascular damage associated with an aorticaneurysms, including in regions of the aorta having arterial branchesthat supply blood to vital organs and tissues, such as thoracic aorticaneurysms, abdominal aortic aneurysms, thoracoabdominal aorticaneurysms, including juxtarenal aortic aneurysms and short-neckabdominal aortic aneurysms.

When reference is made herein to a prosthesis, also referred to hereinas “stent graft,” “stent graft,” or “vascular prosthesis,” to bedelivered, or implanted in a patient, the word “proximal” means thatportion of the prosthesis or component of the prosthesis that isrelatively close to the heart of the patient and “distal” means thatportion of the prosthesis or component of the prosthesis that isrelatively far from the heart of the patient.

When, however, reference is made to a delivery system or a component ofa delivery system employed to deliver, or implant, a prosthesis, theword, “proximal,” as employed herein, means closer to the clinicianusing the delivery system. When reference is made to a delivery systemor a component of a delivery system, “distal,” as that term is employedherein, means, further away from the clinician using the deliverysystem.

For clarity, the word “proximate” means “close to,” as opposed to themeanings ascribed to “proximal” or “distal” described above with respectto either the prosthesis or a delivery system.

One embodiment of a stent graft delivery system of the invention isshown in FIG. 1A through 1F. As shown therein, stent graft deliverysystem 10 includes stent graft 12 of the invention. Stent graft 12includes luminal graft component 14 having proximal open end 16, distalopen end 18, and outside surface 20. Inside surface 22 defines a lumenabout longitudinal axis 26. Luminal graft component 14 is fabricated ofa suitable material, such as is known in the art. Examples of suitablematerials include expanded polytetrafluoroethylene (ePTFE) andpolyethylene terephthalate (PET), such as woven polyester.

Stents 28 of stent graft 12 are distributed radially about luminal graftcomponent 14 and longitudinally along luminal graft component 14. Stents28 include struts 30 that are joined at either end to defined proximalapices 32 and distal apices 34. Stents 28 are fabricated of a suitablematerial, such as is known in the art. In one embodiment, stents 28 arefabricated of a material that causes stents to radially self-expand uponrelease from radial constraint. Examples of suitable materials of radialself-expanding stents include a shape memory alloy, such as Nitinol.Examples of stents not formed of a shape memory alloy include thoseformed of stainless steel. In embodiments of the invention that do notemploy a shape memory alloy, or are otherwise not radiallyself-expanding, a balloon catheter, for example, can be employed toradially expand stents that have been released from radial constriction,as is known in the art. Stents 28 can also include a radiopaquecomponent, as is known in the art, such as at least one radiopacifierselected from the group consisting of barium sulfate, bismuth, tungsten,platinum-iridium and tantalum-tungsten.

Ligatures 36 extend about luminal graft component 14 and include ends38,40. Ligatures 36 are formed of a suitable material, such as is knownin the art. Examples of suitable materials of ligatures 36 includepolyester, and nylon. As shown in FIG. 1A, ends of ligatures 36 includeligature loops 42,44. Ligature loops 42,44 are linked, such as by wire46, as shown in FIG. 1A, to constrict the diameter of stent graft 12. Asrepresented in FIG. 1A, ligatures 36 extend between stents 28 andluminal graft material 14, and traverse struts of stents 28, whereligatures 36 extend between stents 28 and luminal graft material 14. Oneither immediate lateral side of wire 46, ligatures 36 traverse struts30 by passing over a radially outwardly-facing portion 48 of struts 30.Anchor loops 50,52 are distributed longitudinally on either side of theportion of wire 46 and ligature loops 42,44 of ligatures 36 and,consequently, span ligature loops 42,44 to stabilize wire 46, at leastin part, from lateral migration of wire 46 about the periphery of stentgraft 12. Ligatures 36 are formed of a suitable material, such as isknown in the art. Examples of suitable materials of ligatures 36include, for example, stainless steel or a shape-memory alloy, such asNitinol. Likewise, anchor loops 50,52 are formed of a suitable material,such as a material suitable for fabrication of ligatures 36. It is to beunderstood that, in certain other embodiments, anchor loops 50,52 arenot present, such as in embodiments where ligatures 36 are stabilized atstent graft 12 by, for example, being threaded between luminal graftcomponent 14 and struts 30, thereby substantially preventing lateralmigration of wire 46 when wire 46 is linking end 38,40 of ligatures 36.

Returning to FIG. 1A, wire 46 extends through loops 42,44 of ligatures,thereby linking ends 38,40 of ligatures 36 and maintaining stent graft12 in a radially constricted position. It is to be understood that, whenstents 28 are formed of a shape-memory metal alloy, such as Nitinol,then ligatures 36 hold stents 28 in a radially-constricted position,wherein radially self-expanding stents 28 exert a radially outward forceagainst ligatures 36. It is also to be understood that, in alternativeembodiments, ligatures 36 can traverse struts 30 between struts 30 andluminal graft component 14, or about radially outwardly-facing portion48 of struts 30, in different arrangements than that shown in FIG. 1A.Further, it is to be understood that ligatures 36 can pass through thefabric of luminal graft component 14 into lumen 24 in variousembodiments, such as in an embodiment wherein wire 46 extends throughlumen 24 and against the inside surface of luminal graft component 14,as opposed to outside surface 20 of luminal graft component 14. Also,alternatively, in certain embodiments (not shown), stents 28 can besecured to luminal graft component 14 at inside surface 22 of luminalgraft component 14, in which case wire 46 would, in one possibleembodiment, extend within lumen 24, and ligatures 36 would traversestruts 30 between struts 30 and the inside surface of luminal graftcomponent 14. Other arrangements between wire 46, ligatures 36 andstents 28 are also possible.

FIG. 1B is an end view of stent graft 12, as shown in FIG. 1A, takenalong line 1B-1B. As can be seen in FIG. 1B, constricted open stentgraft 12 has an inside diameter of D′. FIG. 1C is a side view of thestent and luminal graft component at proximal open end 16 of stent graft12 shown in FIG. 1A, as viewed from line 1C-1C of FIG. 1B. LikewiseFIGS. 1D, 1E, and 1F, show side views of the most proximal stent ofstent graft 12, shown in the end view of FIG. 1B, taken along lines1D-1D, 1E-1E and 1F-1F, respectively. Collectively, FIGS. 1A-1F showligatures 36 extending about the perimeter of stent graft 12 and betweenstruts 30 and luminal graft component 14, except for struts 30 on eitherlateral side of wire 46, where ligatures 36 pass over anoutwardly-facing portion 48 of struts 30.

FIG. 2A is a side view of stent graft 12 shown in FIG. 1A, but followingretraction of wire 46 from anchor loops 50,52 and loops 42,44 ofligatures 36, thereby allowing radial expansion of stents 28 from theconstricted position, shown in FIGS. 1A-1F, to an expanded position,shown in FIG. 2A. Radial expansion of stents 28, such as by expansion ofradially self-expanding stents 28 fabricated of, for example, Nitinol,causes ends 38,40 and, specifically, loops 42,44 of ligatures 36 toseparate from each other and from anchor loops 50,52 longitudinallyspanning wire loops 42,44 where wire 46 had previously linked loops42,44 between anchor loops 50,52. FIG. 2B is an end view of stent graft12 of FIG. 2A, taken along line 2B-2B, showing an expanded internaldiameter D″ following release of stent graft 12 from the radiallyconstricted position represented in FIGS. 1A-1F. FIGS. 2C, 2D, 2E and 2Fshow side views of the most proximal stent and the luminal graftcomponent at proximal open end 16 represented in FIG. 2B, taken alonglines 2C-2C, 2D-2D, 2E-2E, and 2F-2F respectively.

FIG. 3A is a side view of another embodiment of the stent graft deliverysystem of the invention. As shown therein, stent graft delivery system60 additionally supports ligatures 36 by ligature sutures 62,64 at stentgraft 12 between each loop 42,44 and struts 30 they traverse on eitherside of wire 46. The arrangement of ligature sutures 62,64 between loops42,44 and respective struts 30 traversed by ligatures 36 stabilizeslinkage of loops 42,44 by wire 46. It is to be understood that, in stillanother embodiment, ligature sutures 62,64 can be employed in thealternative to anchor loops 50,52 to thereby stabilize loops 42,44 whenlinked by wire 46. FIG. 3B is an end view of proximal open end 16 ofstent graft 12 shown in FIG. 3A, taken along line 3B-3B, and showinginside diameter D′ of most radially constricted stent graft 12. FIGS.3C, 3D, 3E and 3F, show side views of the most proximal stent 28 andluminal graft component at proximal open end 16 shown in cross-sectionin FIG. 3B, taken along lines 3C-3C, 3D-3D, 3E-3E, and 3F-3F,respectively.

FIG. 4A is a side view of stent graft delivery system 60 shown in FIG.3A, following retraction and withdrawal of wire 46 from anchor loops50,52 and linkage of loops 42,44. As can be seen therein, radialexpansion of stents 28 from a radially constricted position to aradially expanded position causes loops 42,44 to laterally separate fromeach other and, as shown in FIG. 4A, to retract from the ligaturesutures 62,64, respectively. FIG. 4B is an end view of the stent graftin a radially expanded position, as shown in FIG. 4A, taken along line4B-4B, showing the expanded inside diameter D″ following radialexpansion of stent 28 at that section. FIGS. 4C, 4D, 4E, and 4F, showside views of the most proximal stent 28 and luminal graft component 14at the most proximal stent 28 shown in cross-section in FIG. 4B, takenalong lines 4C-4C, 4D-4D, 4E-4E, and 4F-4F, respectively.

FIG. 5A is a side view of yet another embodiment of a stent graftdelivery system of the invention. As shown in FIG. 5A, stent graftdelivery system 70 includes ligatures 72 at each stent 74 of stent graft94. Ligatures 72 include two component parts 76,78, each of which issecured at separate struts 80,82 of respective stent 74. Ligatures 72include loops 84,86 at each end that are aligned by wire 92, whichpasses through them, thereby maintaining stent graft 94 in a constrictedposition. Ligature parts 76,78 are stabilized by anchor loops 100,102longitudinally spanning loops 84,86 when wire 92 is threaded throughloops 84,86, thereby radially constricting stents 74. Although notshown, it is to be understood, that ligature sutures can, optionally,also be employed, as described with respect to FIGS. 1A and 3A. FIG. 5Bis an end view of the stent graft delivery system 70 shown in FIG. 5A,taken along line 5B-5B, showing an internal diameter D′ of stent graft94 in a radially constricted position. FIGS. 5C, 5D, 5E, 5F, show sideviews of the most proximal stent 74 and the portion of the luminal graftcomponent at the most proximal stent 74, shown in FIG. 5B taken alonglines 5C-5C, 5D-5D, 5E-5E and 5F-5F, respectively.

FIG. 6A is a side view of stent graft 94 shown in FIG. 5A, followingretraction of wire 92 from anchor loops 100,102 and loops 82,84 ofligatures 72, thereby allowing stent graft 94 to radially expand fromthe radially constricted position, shown in FIGS. 5A-5F, to a radiallyexpanded position, shown in FIG. 6A. As can be seen in FIG. 6A, loops84,86 laterally separate from each other, and from anchor loops 100,102upon radial expansion of stent graft 94 from the radially constrictedstate to the expanded state. FIG. 6B is an end view of stent graft 94shown in FIG. 6B, taken along line 6B-6B, showing a radially expandedinternal diameter D″ of stent graft 94. FIGS. 6C, 6D, 6E, and 6F, showside views of the most proximal stent 74 and the portion of luminalgraft component 95 most proximate to the most proximal stent 74, shownin FIG. 6B, taken along lines 6C-6C, 6D-6D, 6E-6E, and 6F-6F,respectively.

In another embodiment, circular ligatures 160 extend about the peripheryof stent graft 12 to form distally opposed ends 162,164 of circularligatures 160 that are linked by wire 46. Wire 46 is stabilized byanchor loops 50,52 at the stent graft as shown in FIGS. 7A, 7F.

As shown in FIGS. 8A through 8D, stent graft 10 can include at least oneproximal fenestration 53 (FIG. 8A), a scalloped proximal open end 54(FIG. 8B), a scalloped distal open end 55 (FIG. 8C) and a scallopedproximal and distal open ends 54,55, respectively (FIG. 8D). Althoughnot shown, stent graft 10 can include at least one fenestration incombination with at least one of a scalloped proximal open end and ascalloped distal open end. In additional embodiments, the stent graftsof the invention can include a bare stent at at least one of theproximal open end and distal open end that, optionally, include barbs atrespective proximal or distal apices (not shown).

FIG. 9 is an exploded side view of another embodiment of the stent graftdelivery system of the invention. As shown therein, stent graft deliverysystem 110 includes guidewire catheter 112 having proximal end 114 anddistal end 116. Proximal handle 118 is fixed to proximal end 114 ofguidewire catheter 112. Nose cone 120 is fixed to distal end 116 ofguidewire catheter 112. Wire 122 includes proximal end 124 and distalend 126. Wire 122 can be fabricated of a suitable material, such as isknown in the art, including, for example, Nitinol or some other shapememory alloy. Wire 122 is sufficiently flexible not to injure thepatient during advancement to an aortic aneurysm of a patient. Wirehandle 128 is fixed at proximal end 124 of wire 122. Introducer sheath130 includes proximal end 132 and distal end 134, and distal handle 136is fixed to proximal end 132 of introducer sheath 130. Stent graft 138includes proximal end 140, distal end 142, luminal graft component 144,stents 146 distributed along luminal graft component 144, and ligatures148, arranged and configured as discussed above.

FIG. 10A is an assembled side view of stent graft delivery system 110shown in FIG. 9 , wherein stent graft 138 has been loaded within distalend 134 of introducer sheath 130, and radially constricted, at least inpart, by wire 122 threaded through loops 150 at ends of ligatures 148,as discussed above, and through stabilizing anchor loops 153. In anembodiment, stent graft 138 includes fenestration 139. In a method ofthe invention, stent graft delivery system 110 is advanced to arterialaneurysm 152 of a patient. In one embodiment, shown in FIG. 10A,introducer sheath 130 is advanced to aneurysm site 152 to thereby placestent graft 138 at arterial aneurysm 152. As can be seen in FIG. 10B,distal handle 136 is retracted in a proximal direction indicated byarrow 160 toward proximal handle 118, thereby retracting introducersheath 130 from stent graft 138 at aneurysm 152. As can be seen in FIG.10B, despite retraction of introducer sheath 130, stent graft 138 ismaintained in a radially constricted position by wire 122 extendingthrough ligature loops 150 of ligatures 148 traversing struts of stents146 distributed longitudinally along stent graft 138. It is to beunderstood, however, that in alternative embodiments, stent graftdelivery system 110 can be advanced within an artery to a positiondistal to arterial aneurysm 152, wherein stent graft 138 is directed toarterial aneurysm 152 by advancement of proximal handle 118 and wirehandle 128 in a distal direction indicated by arrow 162 toward distalhandle 136 to thereby direct radially constricted stent graft 118 fromintroducer sheath 130 to arterial aneurysm 152.

Following direction of stent graft to a position that spans aneurysm152, and at least partial rotational and axial alignment of stent graftat aneurysm 152, wire 122 is partially retracted from loops 150 ofligatures and from anchor loops 153. Proximal retraction of wire handle128 toward proximal handle 118, in the direction indicated by arrow 160,as can be seen in FIG. 10C. Continued retraction of wire 122 withdrawswire 122 from all of suture loops 150 of ligatures 148 and anchor loops153, thereby enabling stent graft 138 to fully expand from its radiallyconstricted state, shown in FIG. 10B, to a radially expanded state,shown in FIG. 10D. In an embodiment, stent graft 138 is positioned sothat fenestration 139 is properly aligned with arterial branch 154 forsubsequent placement of branch prosthesis 156 through fenestration 139to arterial branch 154. Thereafter, stent graft 138 is fully implantedwithin aneurysm, and the remainder of stent graft delivery device 110 isretracted from stent graft 138 and the patient, as shown in FIG. 10E,thereby completing treatment of aneurysm site 152 of the patient by themethod of the invention.

Vascular prostheses implanted by the stent graft systems and methods ofthe invention can be implanted, for example, by transfemoral access.Additional branch prostheses that are directed into the vascularprostheses of the invention can be implanted, for example, bysupraaortic vessel access (e.g., through the brachial artery), or bytransfemoral access, or access from some other branch or branches ofmajor blood vessels, including peripheral blood vessels.

The teachings of all patents, published applications and referencescited herein are incorporated by reference in their entirety. Therelevant teachings of all patents, published applications and referencescited herein are incorporated by reference in their entirety. Therelevant teachings of U.S. Pat. Nos. 8,292,943; 7,763,063; 8,308,790;8,070,790; 8,740,963; 8,007,605; 9,320,631; 8,062,349; 9,198,786;8,062,345; 9,561,124; 9,173,755; 8,449,595; 8,636,788; 9,333,104;9,408,734; 9,408,735; 8,500,792; 9,220,617; 9,364,314; 9,101,506;8,998,970; 9,554,929; 9,439,751; 9,592,112; 9,655,712, 9,827,123,9,877,857, 9,907,686; U.S. patent application Ser. Nos. 14/575,673;15/166,818; 15/167,055; 14/272,818; 14/861,479; 15/478,424; 15/478,737;15/587,664; 15/604,032; 15/672,404; 15/816,772; 15/839,272; 15/417,467;PCT/US2017/025844; PCT/US2017/025849; PCT/US2017/025912;PCT/US2017/034223 and PCT/US2017/046062, are also incorporated byreference in their entirety.

The relevant teachings of International Application Numbers:PCT/US2018/019355; PCT/US2018/019344; PCT/US2018/019349;PCT/US2018/019353; PCT/US2018/019354; PCT/US2018/019352;PCT/US2018/019350; PCT/US2018/019356; PCT/US2018/019351;PCT/US2018/019510, are also incorporated by reference in their entirety.

While example embodiments have been particularly shown and described, itwill be understood by those skilled in the art that various changes inform and details may be made therein without departing from the scope ofthe embodiments encompassed by the appended claims.

What is claimed is:
 1. A method of implanting a stent graft at ananeurysm site of a subject, comprising the steps of: a) advancing astent graft through an artery to an arterial aneurysm of a subject, thestent graft including at least one ligature extending at least partiallyabout a periphery of the stent graft and traversing struts of a radialstent of the stent graft, the stent graft including a plurality ofradial stents, the ligature having ends that are linked by a wireextending parallel to a longitudinal axis of the stent graft and throughanchor loops that are distributed longitudinally along a luminal graftcomponent of the stent graft and thereby longitudinally span the linkedends of each associated ligature when the ends of each associatedligature are linked by a wire, thereby causing each associated ligatureto radially constrict each corresponding stent and thereby maintain thestent graft in a radially constricted position, the pair of anchor loopsthereby stabilizing the wire and preventing lateral migration of thewire during implantation of the stent graft; and b) retracting the wirefrom the ends at least one ligature and the anchor loops, consequentlyreleasing the ends of the ligature from each other, the stent graftradially expanding from the radially constricted position to a radiallyexpanded position, thereby implanting the stent graft prosthesis at thearterial aneurysm of the subject.
 2. The method of claim 1, wherein a)the luminal graft component includes a proximal open end and a distalopen end, and b) the plurality of stents are distributed longitudinallyalong the luminal graft component.
 3. The method of claim 1, whereineach of the ligatures extends completely about a circumference of thestent when the ends are linked by the wire.
 4. The method of claim 1,wherein the ends of the ligature each include a ligature loop.
 5. Themethod of claim 1, wherein at least a portion of the ligatures are eachcircular and can be linked at diametrically opposed points by a wirethreading the anchor loops when the ligature is radially constrictingthe luminal graft component.
 6. The method of claim 1, further includingligature sutures arranged laterally at the luminal graft componentthrough which the ligature ends pass, the ligature sutures being locatedon either lateral side of the wire passing through the anchor loops, andwherein the ligature ends are linked by the wire between the ligaturesutures.
 7. The method of claim 1, wherein the ligature includes twoligature component parts that extend partially about the circumferencewhen the ends are linked, and wherein the ligature ends are linked. 8.The method of claim 7, wherein the ligature ends each include a ligatureloop.
 9. The method of claim 8, wherein the two component parts of theligature are each fixed to the luminal graft component.
 10. The methodof claim 8, wherein the two component parts of the ligature are fixed toa strut at an end opposite to the ligature loop of each component partof the ligature.
 11. The method of claim 10, further including ligaturesutures arranged laterally at the luminal graft component through whichthe ligature ends pass, the ligature sutures being located on eitherside of the wire and passing through the anchor loops, and wherein theligature ends can be linked by the wire between the ligature sutures.12. The method of claim 7, wherein the two component parts are each acircular thread that is secured to the luminal graft component or astrut of the associated stent at a point diametrically opposite thepoint of the circular thread that is linked to the circular thread ofthe other component part of the ligature.
 13. The method of claim 1,wherein the ligature is a thread.
 14. The method of claim 13, whereinthe thread includes at least one member of the group consisting ofpolyester, nylon, expanded polytetrafluoroethylene (ePTFE),polyvinylidene fluoride (PVDF), and polypropylene.
 15. The method ofclaim 1, wherein the stent includes a shape-memory alloy.
 16. The methodof claim 15, wherein the shape-memory alloy includes nitinol.
 17. Themethod of claim 16, wherein the stent further includes a radiopaquematerial.